1. Field of the Invention
This invention relates to printing heads for ink jet printers and more particularly to a method of fabricating drop-on-demand ink jet printing heads.
2. Brief Description of the Prior Art
Many varieties of ejection systems for ink drop printers have been devised in an effort to achieve higher speed of operation while providing uniform dimensions of the ink droplets. It is important that the ink droplets be precisely controlled in size and ejected with sufficient velocity that the imprint on the medium is sharp and positioned with great accuracy.
For optimum operation such ink jet printing heads must be small in size and in particular require a minute shallow ink chamber to permit operation at higher drop repetition rates while maintaining relative uniformity in the size of the droplets. The necessary shape and small size makes fabrication difficult, particularly in quantity production. Various fabrication schemes have been used but none with complete satisfaction for the fabrication of ink jet printing heads having an annular ink channel. A print head of this general type is disclosed in U.S. Pat. No. 3,857,049 to Zoltan.